Hydroplaning is caused by a combination of standing water on the road, car speed, and under-inflated or worn-out tires.

Concatenation of text means adding a word with other word. It can be done using Ampersand (&).

For example :

'Amper' & 'sand' = Ampersand 

Wireless transmission can be done via any of the Infrared waves, Radio waves or Microwaves.

In the mesh topology, each computer is connected to the other with a separate physical link in a network. It is most reliable topology as the network does not get down in case one of the nodes is failed.